I see. No, MMU can't perform sound DMA, not with a standard motherboard design. It can't because it is not connected to the RAM data bus (MMU only controls RAM, it doesn't read or write to RAM). Only Shifter is connected directly to RAM, and this is why the task is assigned to Shifter in the first place. You can, of course, redesign the board and connect MMU to RAM data. But that would mean bringing 16 extra signals and adding 16 extra pins to MMU. I don't know why Wolfgang told you it is possible. May be there was some kind of misunderstanding.exxos wrote: ↑Sat May 18, 2019 11:15 amSTE DAC & DMA initially. The suska is essentially a STE. So if I start using the suska cores on the remake project, we are essentially building a STE.
The digital side of the DMA is all done in the FPGA core. the DAC side is output by the FPGA via a serial interface to a external DAC chip, which replaces all the "clutter" in the STE's DAC circuit.
But honestly, I'm not sure it is a good idea to implement STE sound DMA on a system without a full STE Shifter. You are building a configuration that would create compatibility problems and most software won't use sound DMA in such an hybrid anyway.
Not sure fixing Suska code is a realistic goal. Cycle accuracy needs to be an integral part of the design since day one. Now it might require redoing the cores from scratch.This needs looking into as Wolfgang is not aware of wait states, so it would need someone like yourself to work out how to patch the cores.
Suska Isn't a accurate core, the CPU is not cycle accurate, so the timings are already off. It doesn't run Troeds Closure demo, as it cannot work out the wait states on the suska core. But we have no idea where this problem is.
That shouldn't be a big problem.Of course any hardware changes, like boosting the CPU like my accelerators do, it already breaks a lot of time in critical demos etc. What I am talking about is having a FPGA based MMU,GLUE,BLITTER, which will emulate a stock system 100% at 8Mhz. Then we can run them faster at say 32MHz at the flick of a switch, and the system will of course be massively faster.
I will reply to the next message later